Bathroom sink

My old bathroom sink was steel and had 4 metal tabs on the corners that held screw-on clamps so you could attach it to the vanity surface. The sink I want to buy is a ceramic sink with no attachment points whatsoever. The guy in the hardware store says you just calk it in place and it won't move. I find that hard to believe: Once I start scrubbing it or standing on it to paint the ceiling or something I just can't belive a simple bead of ordinary bathroom calking is going to hold that sink in place.

Is a bead of calk going to do the trick or is there something else I need?